Course formation apparatus

ABSTRACT

A course formation apparatus is disclosed having an article feed for conveying the articles to a course formation station. A stop means projects into the path of the articles to engage and stop the movement of one of the articles to form a first article in the course. A bobbing finger element periodically projects into the path of the articles at an upstream position to determine if the position is occupied by a stationary article that has built up behind the first article of the course indicating that a full course has been formed.

United States Patent Lunden [54] COURSE FORMATION APPARATUS [72] Inventor: Sidney L. Lunden, Spokane, Wash.

[73] Assignee: Moore-1cm, 1nc., Spokane, Wash.

[22] Filed: Dec. 31, 1970 [21 1 Appl. No.: 103,020

[52] US. Cl ..l98/40, 144/2 A [51] Int. Cl ..B65g 43/08 [58] Field of Search....198/2l, 31 AB, 34, 40; 53/61; 144/2 A [56] References Cited UNITED STATES PATENTS 2,771,177 11/1956 Cutter ..198/40X 1 Oct. 10, 1972 FOREIGN PATENTS OR APPLICATIONS 641,978 2/1937 Germany ..l98/3l AB Primary Examiner-Edward A. Sroka Attorney-Wells, St. John & Roberts [5 7] ABSTRACT A course formation apparatus is disclosed having an article feed for conveying the articles to a course formation station. A stop means projects into the path of the articles to engage and stop the movement of one of the articles to form a first article in the course. A

bobbing finger element periodically projects into the path of the articles at an upstream position to determine if the position is occupied by a stationary article that has built up behind the first article of the course indicating that a full course has been formed.

9 Claims, 6 Drawing figures PATENTEUHBI 10 I972 lai INVENTOR.

SIDNEY L. LUNDEN ATTYJ.

COURSE FORMATION APPARATUS BACKGROUND OF THE INVENTION This invention relates to course formation apparatus and more particularly to apparatus for forming a course or layer of articles preliminary to stacking the courses one on top of another.

Most lumber stacking equipment includes apparatus for closely grouping a number of boards into a course having a desired width or a selected number of boards and then stacking the courses one on top of another to form a lumber stack. Generally, each course is individually formed at a course formation station and then placed on a preceding course at a stacking station. The course is frequently formed on a table or platform with the boards being individually fed to the platform to build up a course. Most prior course formation apparatus moved each board forward against a preceding board to in turn move the preceding boards forward until the first board in the course reached a stop or trip mechanism at the front of the platform signalling that a full course had been formed. A conveyor means is operated to remove the course from the platform.

Such course formation apparatus is dependent upon the first board reaching the front of the platform with all of the succeeding articles abutting each other in series. Such apparatus, although widely used, has not been totally satisfactory. If one of the boards become askewed on the platform the first board may prematurely reach the stop or trip mechanism without the course being totally formed. Consequently, a deficient course may be included in the stack. Such a deficient course or layer may not be ableto properly support subsequent courses, causing the subsequent layers or courses to slide off the stack and onto the ground.

One of the principal objects of this invention is to provide a course formation apparatus which has a conveyor means extending beyond a last article position of a course to build up the course starting forward of the last article position with a mechanism for sensing the presence of a stationary article at the last article position to determine when a full course has been formed.

An additional object is to provide a course formation apparatus having a feeler mechanism for physically sensing the presence of a stationary article at the last article position of the course without hindering the movement of preceding articles past the last article position.

A further object of this invention is to provide a very simple, reliable, and inexpensive mechanism for a course formation apparatus to detect when the last article in a course is present.

An additional object of this invention is to provide a physical sensing device for a course formation ap paratus that is capable of differentiating between a stationary article and a moving article.

These and other objects and advantages of this invention will become apparent upon the reading of the following detailed description of a preferred embodiment.

BRIEF DESCRIPTIONQF THE DRAWINGS A preferred embodiment of this inventionis illustrated in the accompanying drawings, in which:

invention and illustrating the physical sensing mechanism for detecting the presence of a stationary article in the formation of a course;

FIG. 2 is a fragmentary perspective view of a finger element of the physical sensing device for engaging the articles as they move past an upstream position of the course;

FIG. 3 is a fragmentary side view showing the finger element engaging a moving article;

FIG. 4 is a side view similar to FIG. 3 except showing the finger element engaging a stationary article;

FIG. 5 is a side view similar to FIGS. 3 and 4 except showing a course conveying means for removing a formed course from the course formation apparatus; and

FIG. 6 is an electrical schematic.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Now, referring in detail to the drawing, there is shown in FIG. 1 a portion of a stacking machine having a course formation apparatus 10 for successively receiving articles such as boards and gathering the articles into groups to constitute a course and then successively stacking each course to form a stack.

The course formation apparatus 10 has a general frame 12 with uprights 13 supporting a platform 14 on which the articles are gathered to form a course 18. The course formation apparatus includes an article conveyor 20 for feeding the articles individually onto the platform 14 and for moving the articles forward toward the front of the frame. The article conveyor 20 includes a continuous chain 21 movably mounted on a drive sprocket 24 and an idler sprocket 25 to define an upper flight 22 that extends forward on the table to a location adjacent the front of the platform. The upper flight 22 rides in a channel 23 formed in the platform 14 with the upper profile of the chain extending above the platform to engage the bottom surface of the articles 11. The drive sprocket 24 is mounted on a drive shaft 26 that is rotated at a selected R.P.M. by a motor that is not shown.

The course formation apparatus has a stop means 31 mounted on the frame 12 at the front for projecting into the path of the articles for engaging the first article in a course and stopping its forward movement. When FIG. I is a fragmentary side'view of a course formation apparatus embodying the principal features of this the first article engages the stop means 31, it remains stationary, causing the other succeeding articles to build up behind the first article to form a course. For purpose of illustration, when the first article engages the stop means, it then occupies a first article position 32. A course is complete when a sufficient number of articles are built up behind the first article.

The course formation apparatus 10 further includes a course sensing means 35 for detecting when a course has been formed on the platform and a conveying means 36 (FIG. 5) for removing a formed course from the platform. 1

The course conveying means 36 includes arms 37 that are normally located below the level of the platform 14 and which are raised by an. operatively connected motor 38 (FIG. 6) to lift a formed course above the platform and move the course from the course formation apparatus.

The course sensing means 35 includes a physical sensing device 40 mounted on the frame 12 for physically sensing articles residing or moving past a selected article position 33 spaced upstream of the first article position that corresponds to the last article in a course as shown in FIG. 4 or to the first or subsequent articles of a succeeding course. The physical sensing means 40 includes an arm 42 having a selected length that is generally oriented in a somewhat horizontal orientation, parallel with the movement of the boards by the article conveyor 20. The arm 42 has a forward end 43 that extends to a location immediately below the selected article position 33. The arm has a rear end 44 that extends rearwardly to a location adjacent the drive shaft 26. The arm 42 is pivotally mounted on a bracket 46 intermediate its ends 43 and 44 for pivotal movement in a somewhat rocking motion about a transverse axis to move the forward end 43 in a selected path that intersects the path of the moving articles on the article conveyor 20.

It should be noted that the article conveyor extends forward of the selected article position 33, to move the articles forward of the sensing device 40.

The arm end 43 has a forked saddle 48 with parallel sides 50 and 51 separated by a slot 52 (FIG. 2). A cross-over abutment 53 interconnects the ends of the sides 50 and 51 as shown in FIG. 2.

The physical sensing means 40 includes a feeler or finger element 55 that is pivotally mounted on the end 43 intermediate the sides 50 and 51 about a pin 56 that extends through the sides 50, 51 and the finger element 55. The pin 56 defines a transverse pivot axis that is normal to the direction of travel of the moving boards enabling the finger element to pivot in the same direction as the moving boards. The pivotal movement of the finger element 55 on the end 43 is restricted by the cross-over abutment 53 permitting the finger element to move from an upright undeflected orientation which is substantially normal to the path of the moving articles to a downward deflected orientation. The finger element 55 has a finger end 58 that projects into the path of the moving articles for engaging the articles.

The physical sensing means 40 has a biasing means 60 for biasing the finger element 55 to the upright undeflected position. The biasing means 60 includes a weight 61 that is affixed to the finger element and exon the end .44 and a cam 66 that is affixed on the drive v shaft 26 for engaging the cam follower 64 and pivoting the arm 40 in the rocking motion. The cam 66 is -formed in a triangular shape as shown in FIGS. 3 and 4 having equally spaced lobes 67 and equally spaced dwells 68. Since the drive means 63 is operatively connected to the article conveyor 20 through the drive shaft 26, the frequency of movement of the finger element 55 is directly proportioned to the feed speed of the article conveyor 20. In this specific embodiment the finger element 55 moves up and down three times each time the drive shaft 26 rotates one revolution. Various shaped cams could be utilized in lieu of the triangular shaped carn 66.

The arm 42 is balanced to gravity bias the cam follower 64 against the cam 66. The physical sensing means 40 is designed to move the finger element 55 in a normal stroke that is defined by the leverage of the arm 42 and the cam distance between the lobe 67 and dwell 68 to normally project the finger end into the path of the moving articles as shown in FIG. 1.

When the selected article position 33 is unoccupied either temporarily by a moving article or by a stationary article, the cam follower rides on the cam 66 in a normal fashion bobbing the finger end 58 into and out of the path of the moving articles.

When a moving article moves past the selected article position 33 as shown in FIG. 3, the finger end 58 engages the bottom surface of the article and is pivoted forward by the article from the undeflected upright position to the deflected position as shown in FIG. 3. In this manner the finger element does not restrict or hinder the movement of the articles past the selected article position 33. Since the finger end moves forward the stroke of the finger element remains unchanged. The weight 61 biases the finger element to the upright position after the moving article has past the selected article position 33.

After the requisite number of boards have moved past the selected article position, the next article moves to the selected article position 33 abutting the preceeding stationary article, causing the article to stop in the selected article position 33 as shown in FIG. 4. When this condition occurs, the finger end 58 moves upwardly,.engaging the bottom surface of the stationary article at the selected article position limiting the stroke of the finger element and causing the cam follower 64 to lift off the cam 66 preventing the cam follower 64 from engaging the cam 66 at the dwells 68. This causes the finger element 35 to bob in a reduced stroke considerably less than normal.

The physical sensing means 40 further includes a switch means associated with the arm 42 and responsive to the movement of the arm and which is operatively connected to the motor 38 for initiating the operation of the course conveying means 36 to remove the full course from the platform. The switch means includes a proximity switch 70 that is mounted adjacent the path of the arm 42 in which the switch is operated when the arm moves in the full stroke but is not operated when the movement of the arm 42 is restricted by the engagement of the finger element with a stationary article in the selected article position 33 as shown in FIG. 4.

The proximity switch 70 is operatively connected in an electrical circuit to a time delay relay 71 (FIG. 6). The switch 70 is normally closed and is opened when operated. The relay 71 is set to close power contacts 72 in a power circuit 73 that operates the motor 38. The relay 71 is set to close the contact 72 after being energized for a preselected interval that is greater than the time interval between each cycle of the finger element 55. Thus, as long as the finger element moves up and down in'its normal bobbing position the arm 42 will open the switch 70 to prevent the time delay relay 71 from being energized to close the contact 72. However, when a stationary article is engaged by the finger element 55, the switch 70 remains closed a sufficient time to energize the relay 71 to close the contact 72 and energize the motor 38. The motor 38 then raises the arms 37 to remove the formed course from the course formation station. The electrical control could altematively utilize a normally closed switch 70 and a relay 71 that energizes when the switch 70 is not energized for the selected time interval.

It should be noted that course sensing means 35 does not have to be reset after each course is formed. This is a distinct advantage over counters, etc., that count the number of boards passing a certain point and then activate the course removal apparatus after the desire number of boards have passed. Such counters have to be reset after each cycle.

Although in retrospect this invention appears to be extremely simple in design and operation, one may readily appreciate the advancement that this device brings to the art when viewed with existing prior art.

It should be understood that the above described embodiment is simply illustrative of the principles of this invention, and numerous other embodiments may be readily devised by those skilled in the art without deviating therefrom. Therefore, only the following claims are intended to define this invention.

What is claimed is:

l. A course formation apparatus for forming a course of articles from articles that are successively fed to a course formation station, said apparatus comprising:

a frame located at the course formation station;

an article conveying means mounted on the frame for receiving the fed articles and moving the articles forward in a prescribed path at the course formation station;

a stop means mounted on the frame for projecting into the path of the moving articles to engage and to retard the movement of one of the articles to form a first article of a course and to obstruct the forward movement of the subsequent articles to progressively build up a course behind the first article; and

a physical sensing means mounted on the frame for periodically projecting into the path ofthe moving articles at a longitudinal location spaced from the stop means corresponding to a position of a last article in the course or to an article in a succeeding course to physically sense when the articles build up to the longitudinal position without hindering the movement of articles past the longitudinal location; said physical sensing means comprising:

a finger element movably mounted for reciprocal movement in a path intersecting the path of the articles; and

a drive means operatively connected to the finger element for reciprocation to finger element in the intersecting path in a bobbing motion to detect the presence of a stationary article at the location.

2. A course formation apparatus as set out in claim 1 wherein the finger element is additionally mounted for deflection out of the path of the articles when engaging V a moving article.

3. The course formation apparatus as defined in claim 3 wherein the length of movement of the finger element in the intersecting path is less when the finger element engages a stationary article than when the finger element engages a moving article.

4. The course formation apparatus as set out in claim 3 wherein the physical sensing means includes a means responsive to the length of movement of the finger element in the intersecting path to determine when the finger element engages a stationary article at the longitudinal location.

5. The course formation apparatus as defined in claim 4 further comprising a course removal conveyor means operatively connected to the physical sensing means and responsive to the formation of a full course to remove the full course from the course formation station.

6. The course formation apparatus as defined in claim 4 wherein the drive means moves the finger element in a reciprocal bobbing motion having a cycle proportioned to the movement of the articles by the article conveyor.

7. A course formation apparatus for forming a course of articles from articles that are successively fed to a course formation station, said apparatus comprising:

a frame located at the course formation station;

an article conveying means mounted on the frame for receiving the fed articles and moving the articles forward in a prescribed path at the course formation station;

a stop means mounted on the frame for projecting into the path of the moving articles to engage and to retard the movement of one of the articles to form a first article of a course and to obstruct the forward movement of the subsequent articles to progressively build up a course behind the first article; and

a physical sensing means mounted on the frame for periodically projecting into the path of the moving articles at a longitudinal location spaced from the stop means corresponding to a position of a last article in the course or to an article in a succeeding course to physically sense when the articles build up to the longitudinal position without hindering the movement of articles past the longitudinal location; wherein the physical sensing means includes;

an arm movably mounted on the frame having one end adjacent the longitudinal location;

a finger element pivotally mounted on the arm end I for pivotal movement in the direction of the moving articles from an undeflected orientation to a deflected orientation when engaging a movable article;

a drive means operatively connected to the arm for reciprocating the finger element in a selected stroke bobbing into and out of the path of the moving articles at the longitudinal location so that when the finger element engages a moving article the finger element will pivot to the deflected orientation without substantially changing the stroke of the reciprocating finger element and when the finger element engages a stationary article the finger element will remain in the undeflected orientation reducing the stroke of the finger element; and

means responsive to the reduced stroke of the finger element for determining when a full course is formed.

8. A course formation apparatus as defined in claim 7 wherein the drive means has a cam engaging the arm that is operatively connected to the article conveying means for reciprocably moving the finger element in the selected stroke unless the finger element engages a stationary article. 

1. A course formation apparatus for forming a course of articles from articles that are successively fed to a course formation station, said apparatus comprising: a frame located at the course formation station; an article conveying means mounted on the frame for receiving the fed articles and moving the articles forward in a prescribed path at the course formation station; a stop means mounted on the frame for projecting into the path of the moving articles to engage and to retard the movement of one of the articles to form A first article of a course and to obstruct the forward movement of the subsequent articles to progressively build up a course behind the first article; and a physical sensing means mounted on the frame for periodically projecting into the path of the moving articles at a longitudinal location spaced from the stop means corresponding to a position of a last article in the course or to an article in a succeeding course to physically sense when the articles build up to the longitudinal position without hindering the movement of articles past the longitudinal location; said physical sensing means comprising: a finger element movably mounted for reciprocal movement in a path intersecting the path of the articles; and a drive means operatively connected to the finger element for reciprocation to finger element in the intersecting path in a bobbing motion to detect the presence of a stationary article at the location.
 2. A course formation apparatus as set out in claim 1 wherein the finger element is additionally mounted for deflection out of the path of the articles when engaging a moving article.
 3. The course formation apparatus as defined in claim 3 wherein the length of movement of the finger element in the intersecting path is less when the finger element engages a stationary article than when the finger element engages a moving article.
 4. The course formation apparatus as set out in claim 3 wherein the physical sensing means includes a means responsive to the length of movement of the finger element in the intersecting path to determine when the finger element engages a stationary article at the longitudinal location.
 5. The course formation apparatus as defined in claim 4 further comprising a course removal conveyor means operatively connected to the physical sensing means and responsive to the formation of a full course to remove the full course from the course formation station.
 6. The course formation apparatus as defined in claim 4 wherein the drive means moves the finger element in a reciprocal bobbing motion having a cycle proportioned to the movement of the articles by the article conveyor.
 7. A course formation apparatus for forming a course of articles from articles that are successively fed to a course formation station, said apparatus comprising: a frame located at the course formation station; an article conveying means mounted on the frame for receiving the fed articles and moving the articles forward in a prescribed path at the course formation station; a stop means mounted on the frame for projecting into the path of the moving articles to engage and to retard the movement of one of the articles to form a first article of a course and to obstruct the forward movement of the subsequent articles to progressively build up a course behind the first article; and a physical sensing means mounted on the frame for periodically projecting into the path of the moving articles at a longitudinal location spaced from the stop means corresponding to a position of a last article in the course or to an article in a succeeding course to physically sense when the articles build up to the longitudinal position without hindering the movement of articles past the longitudinal location; wherein the physical sensing means includes; an arm movably mounted on the frame having one end adjacent the longitudinal location; a finger element pivotally mounted on the arm end for pivotal movement in the direction of the moving articles from an undeflected orientation to a deflected orientation when engaging a movable article; a drive means operatively connected to the arm for reciprocating the finger element in a selected stroke bobbing into and out of the path of the moving articles at the longitudinal location so that when the finger element engages a moving article the finger element will pivot to the deflected orientation without substantially changing the stroke of the reciprocating finger element and when the finger element engages a stationary article the finger element will remain in the undeflected orientation reducing the stroke of the finger element; and means responsive to the reduced stroke of the finger element for determining when a full course is formed.
 8. A course formation apparatus as defined in claim 7 wherein the drive means has a cam engaging the arm that is operatively connected to the article conveying means for reciprocably moving the finger element in the selected stroke unless the finger element engages a stationary article.
 9. A course formation apparatus as defined in claim 7 further comprising a course conveying means for moving the full course from the course formation station and wherein the responsive means includes a switch means operatively connected to the course conveying means and responsive to the movement of the finger in the reduced stroke for initiating the operation of the course conveying means. 